USB-A ports with 12-watt or QuickCharge 3.0 output: There’s no reason to choose a charger with USB-A ports slower than 12 watts (5 volts, 2.4 amps), because they’re not much less expensive and they offer slower charging to Apple and Android devices.Apple’s MagSafe wireless charger requires 20 watts in order to achieve its full wireless charging speed. But your device will pull only as much power as it’s rated for, so there’s no safety concern about your phone being damaged or overheating when you’re using a more-powerful charger. Phones that support USB Power Delivery (USB PD)-the standard that allows for fast charging over USB-C-generally draw as much as 18 watts, while larger devices can take 45 watts or more. USB-C ports with 18- to 45-watt output: A USB-C port charges most modern phones faster than a USB-A port does (if you’re using the right cable), and it can even charge tablets and laptops.It’s almost always a better value to choose a charger with two or more ports, whether those ports be USB-A, USB-C, or a combination of the two. At least two USB ports: The cost and space savings of a single-port charger aren’t significant enough to justify the limited output.
